共查询到20条相似文献,搜索用时 703 毫秒
1.
Coastal Aquaculture Development in Bangladesh: Unsustainable and Sustainable Experiences 总被引:1,自引:0,他引:1
Coastal aquaculture in Bangladesh consists mainly of two shrimp species (Penaeus monodon and Macrobrachium rosenbergii). Currently, there are about 16,237 marine shrimp (P. monodon) farms covering 148,093 ha and 36,109 fresh water shrimp (M. rosenbergii) farms covering 17,638 ha coastal area. More than 0.7 million people are employed in the farmed shrimp sector and in 2005–2006
the export value of shrimp was 403.5 million USD. Thus, coastal aquaculture contributes significantly to rural employment
and economy but this is overshadowed by negative social and ecological impacts. This article reviews the key issues, constraints
and opportunities of sustainable shrimp farming. In addition we present the results of two case studies from southwestern
coastal areas where shrimp farming originated and central coastal areas where shrimp farming, especially M. rosenbergii, began in recent years. Lessons learned from the review and case studies are considered in the context of recommendations
to encompass a socially equitable and ecologically sound coastal aquaculture. 相似文献
2.
The Environmental Impact of Shrimp Aquaculture: Causes, Effects, and Mitigating Alternatives 总被引:3,自引:0,他引:3
FEDERICO PÁEZ-OSUNA 《Environmental management》2001,28(1):131-140
Attracted by the demand for shrimp in the developed countries, shrimp aquaculture has expanded rapidly, mainly in the subtropical
and tropical lowlands of America and Asia. This work provides a global review and viewpoint on the environmental impacts of
shrimp aquaculture, considering the causes and effects of the siting and operation of shrimp ponds and abandonment of farm
facilities. Additionally, mitigating alternatives are discussed. To date, approximately 1–1.5 million ha of coastal lowlands
have been converted into shrimp ponds, comprising mainly salt flats, mangrove areas, marshes, and agricultural lands. The
impact of shrimp farming of most concern is the destruction of mangroves and salt marshes for pond construction. Compatibility
with other users, the presence of buffer zones, maintaining an acceptable balance between mangroves and shrimp pond area,
improved pond design, reduction of water exchange, and an improved residence time of water, size and capacity to assimilate
effluents of the water body, are examples of ways to mitigate the adverse effects. The use of mangroves and halophytes as
biofilters of shrimp pond effluents offers an attractive tool for reducing the impact in those regions where mangrove wetlands
and appropriate conditions for halophyte plantations exist. Healthy seed supply, good feed with the use of prophylactic agents
(including probiotics), good water quality, and lower stocking densities are examples of actions suggested to control disease
in shrimp farming. Finally, in the context of integrated management, research priorities are suggested. 相似文献
3.
Mangrove ecosystems in Sri Lanka are increasingly under threat from development projects, especially aquaculture. An economic
assessment is presented for a relatively large (42 ha) shrimp culture development proposed for the Rekawa Lagoon system in
the south of Sri Lanka, which involved an extended cost–benefit analysis of the proposal and an estimate of the “total economic
value” (TEV) of a mangrove ecosystem. The analysis revealed that the internal benefits of developing the shrimp farm are higher
than the internal costs in the ratio of 1.5:1. However, when the wider environmental impacts are more comprehensively evaluated,
the external benefits are much lower than the external costs in a ratio that ranges between 1:6 and 1:11. In areas like Rekawa,
where agriculture and fisheries are widely practiced at subsistence levels, shrimp aquaculture developments have disproportionately
large impacts on traditional livelihoods and social welfare. Thus, although the analysis retains considerable uncertainties,
more explicit costing of the environmental services provided by mangrove ecosystems demonstrates that low intensity, but sustainable,
harvesting has far greater long-term value to local stakeholders and the wider community than large shrimp aquaculture developments. 相似文献
4.
Birgit K. Boogaard Bettina B. Bock Simon J. Oosting Johannes S. C. Wiskerke Akke J. van der Zijpp 《Journal of Agricultural and Environmental Ethics》2011,24(3):259-282
Society’s relationship with modern animal farming is an ambivalent one: on the one hand there is rising criticism about modern
animal farming; on the other hand people appreciate certain aspects of it, such as increased food safety and low food prices.
This ambivalence reflects the two faces of modernity: the negative (exploitation of nature and loss of traditions) and the
positive (progress, convenience, and efficiency). This article draws on a national survey carried out in the Netherlands that
aimed at gaining a deeper understanding about the acceptance of modern dairy farming in Dutch society. People take two dimensions
into account when evaluating different aspects of modern dairy farming: (1) the way living beings are used for production
and (2) the way a dairy farm functions as a business. In both these dimensions people appeared to adopt cautious opinions:
most people preferred relatively traditional and natural farms and were concerned about the use of nature and treatment of
animals in modern production—although this did not imply an outright rejection of modern animal farming. The study also looked
for (and sought to explain) differences of opinion between social groups. Besides socio-demographic factors such as age and
gender, farming experience and value-orientation (such as socially minded and professional) appeared to be important variables.
The values and convictions within modern society can help to explain why some people are greatly concerned about animal welfare
while some show less concern. This diversity also helps to explain why general information campaigns are quite ineffective
in allaying concerns about modern animal farming. 相似文献
5.
Joshua Farley David Batker Isabel de la Torre Tom Hudspeth 《Environmental management》2010,45(1):39-51
Humans are rapidly depleting critical ecosystems and the life support functions they provide, increasing the urgency of developing
effective conservation tools. Using a case study of the conversion of mangrove ecosystems to shrimp aquaculture, this article
describes an effort to develop a transdisciplinary, transinstitutional approach to conservation that simultaneously trains
future generations of environmental problem solvers. We worked in close collaboration with academics, non-government organizations,
local government and local communities to organize a workshop in Puerto Princesa, Palawan, Philippines. The primary objectives
of the workshop were to: (1) train participants in the basic principles of ecological economics and its goals of sustainable
scale, just distribution and efficient allocation; (2) learn from local community stakeholders and participating scientists
about the problems surrounding conversion of mangrove ecosystems to shrimp aquaculture; (3) draw on the skills and knowledge
of all participants to develop potential solutions to the problem; and (4) communicate results to those with the power and
authority to act on them. We found that the economic and ecological benefits of intact mangroves outweigh the returns to aquaculture.
Perversely, however, private property rights to mangrove ecosystems favor inefficient, unjust and unsustainable allocation
of the resource—a tragedy of the non-commons. We presented the workshop results to the press and local government, which shut
down the aquaculture ponds to conserve the threatened ecosystem. Effective communication to appropriate audiences was essential
for transforming research into action. Our approach is promising and can be readily applied to conservation research and advocacy
projects worldwide, but should be improved through adaptive management—practitioners must continually build on those elements
that work and discard or improve those that fail. 相似文献
6.
Hydrological and Oceanographic Considerations for Integrated Coastal Zone Management in Southern Belize 总被引:4,自引:0,他引:4
9 m3, a volume equal to the basin. During the rainy season, June–September, 84% of the annual discharge occurs, which causes the
bay to become brackish. Port Honduras serves as an important nursery ground for many species of commercially important fish
and shellfish. The removal of forest cover in the uplands, as a result of agriculture, aquaculture, and village development,
is likely to significantly accelerate erosion. Increased erosion would reduce soil fertility in the uplands and negatively
affect mangrove, seagrass, and coral reef productivity in the receiving coastal embayment. Alternatively, the conservation
of an existing protected areas corridor, linking the Maya Mountains to the Caribbean Sea, is likely to enhance regional sustainable
economic development. This study aims to support environmental management at the scale of the “ecoscape”—a sensible ecological
unit of linked watersheds and coastal and marine environments. 相似文献
7.
ABSTRACTSmall-scale ecological farming and their associated alternative food networks, are increasingly important in China, as a response to poor farm incomes and as a contribution to widespread concerns about environmental degradation and food safety. However, despite the enormous market potential and the notable success of some ventures, this type of farming remains at the margins, with many businesses struggling to develop beyond their start-up phase and consumers struggling to build confidence in the new produce and routes to market. Many of these farms display the classic elements of pioneer businesses, including high reliance on charismatic individuals, insecure land rights, high transaction and monitoring costs and fragile routes to market. Empirically, many of these businesses fail because they cannot grow out of the pioneer phase before the pioneer grows tired of the business. While this is a problem for all small businesses, it is particularly acute in business sectors like ecological farming in China, where there is little evidence of suitable and sustainable developmental models. Using Bernardus Lievegoed's work on organisational development applied to two case study farms, we suggest that there are Western developmental models that are applicable to small-scale ecological farming and that have the potential to offer insights into how this might be achieved with Chinese characteristics. We conclude by arguing that, Chinese ecological farms have to plan explicitly for a form of development that allows them to remain committed to their ideals while moving them away from dependence on charismatic people, family labour and volatile customer bases. 相似文献
8.
Shrimp exports are one of Sri Lanka's major foreign exchange earners and account for 40%–50% of total aquaculture exports.
There has been a recent and rapid expansion of the industry in the Northwestern Province (NWP) of Sri Lanka but the industry
has suffered from disease outbreaks and environmental problems. Currently, shrimp farms cover nearly 3000 ha of the coastal
area of the NWP.
The environmental impacts of shrimp cultivation in general are well known and numerous research studies have been done. However,
little work has been carried out in Sri Lanka. This study provides some necessary background to brackish water shrimp aquaculture
in Sri Lanka. It focuses briefly on the development of shrimp aquaculture and the current status of the industry. Emphasis
is placed on two broader aspects—impacts on the existing wetland ecosystem and on the environment. These impacts are presumed
to be the main causes hindering the growth of the industry and raising widespread public protest. Current ecosystem and environmental
management practices are discussed. Finally, strategic issues for management and sustainable growth are discussed. 相似文献
9.
Issues,impacts, and implications of shrimp aquaculture in Thailand 总被引:11,自引:0,他引:11
Water quality impacts to and from intensive shrimp aquaculture in Thailand are substantial. Besides the surface and subsurface salinization of freshwaters, loadings of solids, oxygen-consuming organic matter, and nutrients to receiving waters are considerable when the cumulative impacts from water exchange during the growout cycle, pond drainage during harvesting, and illegal pond sediment disposal are taken into account. Although just beginning to be considered in Thailand, partial recirculating and integrated intensive farming systems are producing promising, if somewhat limited, results. By providing on-site treatment of the effluent from the shrimp growout ponds, there is less reliance on using outside water supplies, believed to be the source of the contamination.The explosion in the number of intensively operated shrimp farms has not only impacted the coastal zone of Thailand, but has also resulted in an unsustainable aquaculture industry. Abandonment of shrimp ponds due to either drastic, disease-caused collapses or more grandual, year-to-year reductions in the productivity of the pond is common. To move Thailand towards a more sustainable aquaculture industry and coastal zone environment, integrated aquaculture management is needed. Components of integrated aquaculture management are technical and institutional. The technical components involve deployment of wastewater treatment and minimal water-use systems aimed at making aquaculture operations more hydraulically closed. Before this is possible, technical and economic feasibility studies on enhanced nitrification systems and organic solids removal by oxidation between production cycles and/or the utilization of plastic pond liners need to be conducted. The integration of semi-intensive aquaculture within mangrove areas also should be investigated since mangrove losses attributable to shrimp aquaculture are estimated to be between 16 and 32% of the total mangrove area destroyed betweeen 1979 and 1993.Government policy needs to devote as much attention to sustainability issues as it has on promoting intensive pond culture. Such a balanced policy would include training and education monitoring and enforcement, rehabilitating abandoned ponds, managing land use within the coastal zone, more community involvement, and government reorganization to eliminate overlapping jurisdictions among agencies.As integrated aquaculture management becomes more the practice than the exception, less risk of crop failure to the industry and reduced discharge loadings from intensively managed shrimp ponds to receiving waters can be expected. Projected limitations on growing and marketing shrimp in the future, such as scarcity of land and broodstock, continued disease outbreaks, negative publicity, regulatory enforcement, water treatment and solids disposal costs, and increased competition from growers in other Asian countries will also drive the government and the industry towards adopting integrated aquaculture management.The data for this paper was obtained while the senior author was a Visiting Fulbright Researcher at the Coastal Resources Institute (CORIN), Prince of Songkla University, Hat Yai, Songkhla, 90112, Thailand. 相似文献
10.
Earthworms’ body works as a ‘biofilter’ and they have been found to remove the 5 days’ BOD (BOD5) by over 90%, COD by 80–90%, total dissolved solids (TDS) by 90–92%, and the total suspended solids (TSS) by 90–95% from
wastewater by the general mechanism of ‘ingestion’ and biodegradation of organic wastes, heavy metals, and solids from wastewater
and also by their ‘absorption’ through body walls. Earthworms increase the hydraulic conductivity and natural aeration by
granulating the clay particles. They also grind the silt and sand particles, increasing the total specific surface area, which
enhances the ability to ‘adsorb’ the organics and inorganic from the wastewater. Intensification of soil processes and aeration
by the earthworms enable the soil stabilization and filtration system to become effective and smaller in size. Suspended solids
are trapped on top of the vermifilter and processed by earthworms and fed to the soil microbes immobilized in the vermifilter.
There is no sludge formation in the process which requires additional expenditure on landfill disposal. This is also an odor-free
process and the resulting vermifiltered water is clean and disinfected enough to be reused for farm irrigation and in parks
and gardens
G. Bharambe—GU & Research Assistant (Under Rajiv K. Sinha), U. Chaudhari—GU (Worked on vermiculture project). 相似文献
11.
12.
Bergquist DA 《Environmental management》2007,40(5):787-802
This article discusses environmental sustainability in aquaculture and its contribution to poverty alleviation, based on field
studies in Sri Lanka and the Philippines. The aquaculture practices studied are the monoculture of the black tiger prawn (Penneaus monodon) and milkfish (Chanos chanos) and the polyculture of the two species together with the mud crab (Scylla serrata). Factors affecting economic viability, social equity and environmental impacts in aquaculture are discussed and used to
illuminate local and regional differences between aquaculture in Sri Lanka and the Philippines. Findings indicate that the
most significant difference is the level of participation by local people (i.e., people originating ≤10 km away from the farm
location). In the Philippines, 84 % of the people involved in aquaculture are locals, whereas in Sri Lanka, 55% are outsiders.
Whether differences between the two areas can be explained by analyzing regional conditions, which might have resulted in
different aquaculture practices, is discussed. In Sri Lanka, semi-intensive shrimp monoculture is currently the most common
practice, whereas in the Philippines, extensive shrimp/fish polyculture is more common. Previous studies, as well as fieldwork,
indicate that extensive culture practices reduce environmental impacts and benefit local people more. Sustainability in aquaculture
is, however, also dependent on the extent of mangrove conversion into ponds. As such, extensive and locally owned farms do
not necessarily result in an all but sustainable situation. Keeping this in mind, it is discussed if extensive polyculture
practices might result in a more sustainable aquaculture, both environmentally and socioeconomically. 相似文献
13.
Assessing farm-level agricultural sustainability over a 60-year period in rural eastern India 总被引:1,自引:1,他引:0
Agricultural sustainability is a vital parameter to be ascertained locally and globally if food security is to be achieved
and maintained. Agricultural sustainability is the combined product of social, economic and ecological sustainability. It
is also a function of temporal and spatial variations, a fact which indicates that area-specific sustainability indices need
to be designed. We present here an Agricultural Sustainability Index (ASI) for rural eastern India and use it to calculate
the ASI for 150 farms for three decades over a 60-year period, viz., 1950–1960, 1980–1990 and 2000–2010 for a representative
Indian village of Gangapur (25°83′N, 85°65′E). The ASI was calculated using 30 variables, 10 each of social, economic and
ecological sustainability. An extensive questionnaire-based survey was carried out to collect the relevant data. Our study
reveals that over a 60-year period, ASI values do not show a statistically significant change. We conclude that the agricultural
practices of the region have maintained sustainability so far although the scope for improvement in several broad areas identified
by us is immense. Increased ecological literacy and better implementation of government policies, aiming at health, education
and better scientist–farmer interactions, must target improved ASI values in coming decades. 相似文献
14.
Forster DL 《Journal of environmental quality》2002,31(1):32-37
This paper summarizes research that investigates the effects of alternative farming practices on the performance of Lake Erie basin farms. First, data from a representative panel of about 100 farmers is analyzed to determine how conservation tillage, rotations, and other factors affected farms' economic returns during 1987-1992. Statistical analysis of these data is unable to demonstrate that there is any significant relationship between farming system (i.e., tillage and rotation) variables and farm profitability. Next, a farm-level bioeconomic simulation model is used to analyze the effects of conservation tillage adoption on farm profitability, farm size, and pollutant emissions. Findings are that tillage system, farm size, and crop selection are determined jointly and may substantially improve economic performance of farms. Conservation tillage enables farms to be larger and more specialized, and as a result, farm profitability improves. Statistical analysis of farm panel data is unable to show the effect of tillage on profitability because it neglects to account for endogeneity of variables (or joint effects of tillage, size, crop selection, and performance) in production decisions. 相似文献
15.
Aram Terchunian Victor Klemas Alberto Segovia Agustin Alvarez Bryon Vasconez Luis Guerrero 《Environmental management》1986,10(3):345-350
A cooperative mangrove mapping project between the Ecuadorian Center for Remote Sensing (CLIRSEN) and the University of Delaware was begun in August 1982. The objectives of the project were to create historical maps of mangrove ecosystem extent and change, while transferring aerial photographic interpretation techniques to Ecuadorian personnel. The result of this cooperation was a series of three 125,000 scale maps of historical mangrove extent and change from 1966 to 1982 in the southern Gulf of Guayaquil. This multitemporal study showed a 16% decrease in mangrove extent and a 27% increase in shrimp pond development. If these rates of change prevail into the future, mangroves in Ecuador will reach parity with shrimp ponds in 1984 and completely disappear by mid-1990. Recognizing the significance of this loss to shellfish and fish production along the coast, Ecuadorian scientists at CLIRSEN have subsequently initiated a nationwide mangrove mapping program to create a historical base for future mangrove management strategies. 相似文献
16.
Rajiv K. Sinha 《Journal of Agricultural and Environmental Ethics》1997,10(2):183-197
The Green Revolution in India which was heralded in the 1960‘s was a mixed blessing. Ambitious use of agro-chemicals boosted
food production but also destroyed the agricultural ecosystem. Of late Indian farmers and agricultural scientists have realized
this and are anxious to find alternatives – perhaps a non-chemical agriculture – and have even revived their age-old traditional
techniques of natural farming. Scientists are working to find economically cheaper and ecologically safer alternatives to
agro-chemicals. Blue-Green Algae Biofertilizers, Earthworm Vermicomposts (Vermiculture), biological control of pests and herbal
biopesticides are showing promise. Saline agriculture and sewage farming are also being promoted in India to augment food
production in the face of water scarcity. There is a move to search for alternative foods, which are more nutritious, cheaper
and have shorter harvest cycles. Farm and food policy in India has to change its outlook before there can be a second green
revolution.
This revised version was published online in August 2006 with corrections to the Cover Date. 相似文献
17.
Peter O. Otieno Joseph O. Lalah Munir Virani Isaac O. Jondiko Karl-Werner Schramm 《The Environmentalist》2011,31(4):382-393
The increasing number of incidences of alleged wildlife poisoning with Furadan in Kenya has sparked off a strong lobby fronted
by wildlife conservationists against Furadan use in the country and prompted this study. The worst-case scenario was in 2004
in Athi River, where a massive number of 187 African white-backed vultures (Gyps africanus) and hyenas were found dead at a spot where poisoning was suspected to have occurred through a Furadan-laced camel carcass
bait. This study was initiated by the Peregrine Fund—Africa Project, and the objective was to provide evidence for Furadan
exposure, its misuse and involvement in vulture poisoning and potential impact on areas near two wildlife conservancies in
two most affected districts. The study found evidence for ready availability of Furadan 5G in local veterinary retail shops
and its illegal misuse by pastoralists and farmers against wildlife to protect their animals and crops. Analysis of soil,
water and plants taken from the farms and water sources by high-perfomance liquid chromatography (HPLC) and gas liquid chromatography–mass
spectrometry (GC–MS) found residues of carbofuran, 3-hydroxycarbofuran and 3-ketocarbofuran, indicating that Furadan was used
extensively in farming causing residual environmental distribution and contamination and posing risks to small birds and mammals.
Forensic analysis of residues in beaks, feet and crop content of the dead vultures as well as in a laced camel carcass bait
and soil samples from one site of poisoning also showed carbofuran and its two metabolites supporting allegations of Furadan
involvement in wildlife poisoning and high-mortality cases of African white-backed vultures (Gyps africanus) in Kenya. 相似文献
18.
In different parts of the world, there is an urgent need for redesigning and innovating farming systems. Such a process may be supported by model-based explorations that enable ex-ante evaluation of a broad range of alternatives. Since a variety of viable patterns of farm development exists related to farm resource endowment and farmer's strategy, model-based explorations should be able to capture the existing variation in resource endowment and strategies in order to have impact on strategic farm management. In this paper, we present an overview of the model-based explorative method based on the MILP model Farm Images, applied to explore options for sustainable development of vegetable farms in Canelón Grande, Uruguay. The method is used to gain insight into the impact of current farm resource endowment on the possibilities for sustainable development and on the resource use efficiency at farm scale. We maximized farm income for 128 different farm types in an environment-oriented scenario and in an income-oriented scenario. Farm types were defined by combining 4 farm sizes, 2 labor endowments, 4 irrigation endowments, 2 soil quality combinations and 2 mechanization levels. The results demonstrate a strong impact of farm resource endowment on possibilities for sustainable development, as well as synergy between labor, land and irrigated area on resource-use efficiency at farm scale. Farms with 10ha of land or less, representing 47% of the farms in the Canelón Grande region, could only achieve a family income higher than the average income of Uruguayan families when the irrigated area was ca. 40% of the farm area. The achievement of environmental targets was less costly in terms of income on farms with a low rather than high labor availability per unit area and on farms with irrigation facilities. 相似文献
19.
Local Responses to Inundation and De-Farming in the Reservoir Region of the Three Gorges Project (China) 总被引:1,自引:0,他引:1
Large-scale infrastructural developments in rural areas often impose significant direct and indirect impacts on environment
and people. The Three Gorges Project to dam the Yangtze River in China will create a huge reservoir, inundate farmlands and
villages, and incur large-scale resettlement. The concurrent de-farming program to reforest marginal farmlands on steep slopes
imposes additional stresses on local people. This study evaluates the ecological and economic adjustments in rural areas affected
by both projects, and explores villagers’ knowledge, attitudes, perceptions, and expectations vis-à-vis the drastic changes.
Eleven villages in Yunyang County in Sichuan Province, stratified into three zones based on topography and agriculture, were
assessed by field studies, questionnaire surveys, maps, satellite imagery, and census and government reports. Multiple regressions
identified predictors for 17 dependent variables. Spatial variations in the difficult terrain imposed zone-differentiated
agricultural constraints, ecological impacts, and human responses. The dominant farming population—mainly young adults working
as migrant laborers in cities—has adopted some nonagricultural work to supplement incomes. Expected per-capita standardized
farmland (SF) exceeded threshold SF, which surpasses existing SF. Motivations to reclaim more farmlands, de-farm marginal
lands, and become migrant laborers were explained by different multiple-regression predictors. Reduction in farmland stock
by inundation and de-farming, aggravated by unwillingness towards nonlocal resettlement, would impose ecological pressures
and stimulate demands for nonfarming incomes. Common anticipation of better future income and occupation has been subdued
by unfavorable feedbacks from early relocatees. Future environmental and landscape changes are hinged upon changing human
responses. Government policies could be informed by research findings to match economic, ecological, and social realities. 相似文献
20.
Kirsty L. Holstead Carlos Galán-Díaz Lee-Ann Sutherland 《Journal of Environmental Policy & Planning》2017,19(4):391-407
As the owners of the majority of land in the U.K., farmers are well placed to contribute to renewable energy targets. Media coverage can both drive and reflect farmers’ views about renewable energy but has been largely unexplored to date. This article uses discourse analysis to examine the evolution of coverage of one form of renewable energy – on-farm wind – in the U.K. farming press from 1980 to 2013. We identified a diverse debate with five major discourses. On-farm wind turbines are alternatively represented as: profitable farm diversification opportunities; producers of clean energy; important for rural development and sources of conflict. Although press coverage predominantly encourages wind energy production, a further discourse advises farmers to ‘Proceed with Caution’. While emphasising images and values which have widespread affinity among U.K. farmers, the press have increasingly employed an economic frame, constructing wind energy generation as a farm diversification strategy. The most recent farming press coverage predominantly encourages an instrumental approach to wind energy, crowding out other (non-economic) rationales and marginalising local community concerns. This appears to reflect the financial orientation of recent policy support (particularly Feed-in Tariffs), and may have long-term costs in enabling sustainable energy production systems. 相似文献